The Drainage of Melbourne. 61 



into the street gutters, which may be conveniently 

 termed " house drainage." 



2. That which has been used for motive-power in 

 manufactories, for cooling in breweries, and for baths, 

 termed in the essay " harmless drainage." 

 The essay provides for the treatment of the above in one 

 of two ways : — 



I. Allowed to now directly into the Yarra — Subsoil 



water (a) ; rain water from ' roofs, &c. (61); flood 

 water (63); and harmless drainage (02). 



II. Conveyed through sewers to a filtering area — Street 



drainage (62) and house drainage (ci). 



3. The proposed means for effecting the removal of the 

 drainage are — (1) Street gutters ; (2) storm-water drains ; 

 (3) porous earthenware pipes ; and (4) sewers. By means of 

 these the drainage will be collected and conveyed to its 

 destination by the following arrangements, viz.: — 



I. The Yarra. — Subsoil water (a) to be collected by 

 porous pipes, laid at a sufficient depth to drain house foun- 

 dations and cellars, but not connected with the sewers. 

 Rain water from roofs, &c. (61), and harmless drainage (c 3 ) to 

 flow into the street gutters and be carried off as at present. 

 Flood water (b s ), where the greatest accumulation occurs, 

 to be carried off by underground storm- water drains. 



II. The Filtering Area. — Street drainage, where the 

 traffic is greatest (b 2 ), to be admitted from the gutters into 

 the sewers, the openings being sufficient for only a small 

 quantity of the dirtiest water. Of house drainage (ci), it is 

 remarked, not one drop of offensive waste water ought to 

 escape into the street channel ; it should be intercepted and 

 carried into the sewers. 



4. It is proposed to enlarge the gutters, at the same time 

 widening the street pavements without reducing the avail- 

 able carriage way. The only storm-water drain provided is 

 in Elizabeth-street, which is spoken of as the most important 

 locality to be dealt with. Subsoil water, collected by porous 

 earthenware pipes, is to be allowed to escape into the Yarra 

 at as many points as convenient; but it is remarked that it 

 will not be possible thoroughly to drain cellars in some por- 

 tions of the area, owing to their low level, except by pump- 

 ing. Arrangements for pumping this water do not, however, 

 appear to be included in the scheme. It is particularly 

 pointed out that the subsoil drainage pipes must not com- 

 municate with the sewers. 



